Two NASA
astronauts will make a bit of history next month when they become the first
female spacecraft commanders to lead their orbital missions at the same time.

Veteran
spaceflyers Pamela Melroy and Peggy Whitson will lead a joint
construction mission to the International Space Station (ISS) next month. Melroy
will command the space shuttle Discovery's STS-120 flight to the ISS, where her
seven-astronaut crew and Whitson's
Expedition 16 team aboard the outpost will install a new orbital node.

"I'm
actually very excited about it," Whitson said in an interview.

Whitson, an
accomplished biochemist and soon-to-be first female space station commander,
said she and Melroy have flown together in the past. The spaceflyers last met
in orbit during NASA's STS-112 station assembly mission in 2002, but back then
Melroy served as a shuttle pilot and Whitson an Expedition
5 flight engineer.

"So it
will be fun to sort of rejoin again on orbit, this time with slightly different
roles," said Whitson, 47, who will launch to the ISS Oct. 10 aboard a
Russian Soyuz spacecraft.

Melroy, a
two-time shuttle pilot, and her crew are due to launch toward the ISS on Oct.
23 and dock at the ISS two days later.

"I confess
that I really look forward to that first handshake across that hatch,"
Melroy said of her plans to note the female spaceflight first. "That'll be
all the commemoration that I need is a picture of that."

The joint
shuttle-ISS crew will install the new Harmony
connecting node to serve as a foundation for future international
laboratories. The astronauts will also move the station's Port 6 solar array
segment from its mast-like central perch to the outpost's left-most edge.

"It is
a complicated mission," Melroy, 45, told SPACE.com.
"Essentially, we've got two large pieces of the station that we're doing
assembly operations with, and that's pretty unusual."

A colonel
in the U.S. Air Force, Melroy is the second female shuttle commander and the only
one currently on active duty. Eileen Collins,
NASA's first woman shuttle pilot and commander, retired from the agency last
year.

Melroy does
not expect another female astronaut to command a shuttle mission by NASA's
planned 2010 retirement of its three-orbiter fleet.

"I
think it's pretty unlikely, actually, because we don't have anybody in the
pilot queue who is a woman test pilot," Melroy said. "But I?m hopeful
for the future. I think this may be the first time two women commanders fly in
space, but I'm sure it won't be the last."

Melroy and
Whitson agreed that persistence is key for any young women hoping to join
NASA's astronaut corps or the military. Whitson, a Beaconsfield, Iowa, native
with a doctorate in biochemistry, said she applied to be an astronaut for 10
years straight before finally being accepted.

"I
would certainly encourage young people to pursue their dreams," Whitson
said. "It isn't always an easy path, but it's worth going after. And I figure
if a farmer's daughter from Iowa can become an astronaut, you can be just about
anything you want to be."